1 Introduction

1.1 Project Background

1.1.1.1 The Civil Engineering and Development Department (CEDD) and the Planning Department (PlanD) jointly commenced Agreement, namely the Agreement No. CE 35/2012 (CE) “Planning and Engineering Study for Housing Sites in Yuen Long South – Investigation” in 2012, to formulate the detailed development proposals for the YLS DA. This Study recommends that the sewage generated from the YLS DA will be discharged to separate new sewage treatment work, namely the Yuen Long South Effluent Polishing Plant (YLSEPP) which is located to the southern end of the YLS DA.

1.1.1.2 The above study recommended preliminary treatment capacity, treatment level and discharge arrangement of YLSEPP taking into account the constraints for discharge to North Western Waters and Deep Bay. Further reviews of flow projection, treatment level, treated effluent discharge and sludge treatment scheme shall be carried out to formulate the preliminary design of YLSEPP to cater for the sewage collected from the new developments within the YLS DA and other developments in the North West New Territories (NWNT) to support the medium and long-term housing and economic needs of the NWNT.

1.1.1.3 AECOM Asia Co Ltd. was commissioned by Drainage Services Department (DSD) on 27 March 2020 to carry out this Assignment for the investigation for YLSEPP. Site location plan of the YLSEPP is shown in Figure 1.1.

1.2 Designated Projects under EIAO

1.2.1.1 A Project Profile (No. PP-576/2019) was submitted to the Environmental Protection Department (EPD) on 1 February 2019 for application for an Environmental Impact Assessment (EIA) Study Brief under section 5(1)(a) of the Environmental Impact Assessment Ordinance (EIAO) and the EIA Study Brief No. ESB-313/2019 for the Project was issued on 15 March 2019 under the EIAO.

1.2.1.2 According to Section 5.1 of the EIA Study Brief, a summary highlighting relevant EIA sections fulfilling respective requirements of the EIA study brief and Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM)(in particular Annexes 11 and 20 of EIAO-TM) has been prepared and included in Appendix 1.1.

1.2.1.3 The Project is classified as a Designated Project (DP) under

· Item F.1, Part I of Schedule 2 of the EIAO - Sewage treatment works with an installed capacity of more than 15,000 m³/day.

· Item F.4, Part I of Schedule 2 of the EIAO - an activity for reuse of treated sewage effluent from a treatment plant

1.3 Purpose of the EIA Study

1.3.1.1 The purpose of the EIA Study is to provide information on the nature and extent of the environmental impacts arising from construction and operation of the Project and related activities that take place concurrently. This information will contribute to decisions on:

· the acceptability of potential environmental consequences that are likely to arise as a result of the Project;

· the conditions and requirements for the design, construction and operation of the Project and related activities to mitigate against potential environmental consequences; and

· the acceptability of residual impacts after the proposed mitigation measures are implemented.

1.4 Objectives of this EIA Study

1.4.1.1 The objectives of the EIA study as stated in the EIA Study Brief are as follows:

(i) to describe the Project and associated works together with the requirements and environmental benefits for carrying out the Project;

(ii) to identify and describe elements of community and environment likely to be affected by the Project and/or likely to cause adverse impacts to the Project, including both the natural and man-made environment and the associated environmental constraints;

(iii) to identify and quantify emission sources and determine the significance of impacts on sensitive receivers and potential affected uses;

(iv) to identify and quantify contaminated land within any project area for development works, and to propose measures to avoid disposal in the first instance;

(v) to identify and quantify any potential losses or damages to ecology, flora, fauna and natural habitats;

(vi) to identify and evaluate any potential landscape and visual impacts and to propose measures to mitigate these impacts;

(vii) to identify any potential hazard to life due to generation, storage, utilization, processing and transmission (if applicable) of biogas and other dangerous goods (DGs) during the operation phase of the Project and to propose measures to mitigate these impacts if required;

(viii) to propose the provision of infrastructure or mitigation measures so as to minimize pollution, environmental disturbance and nuisance during construction and operation of the Project;

(ix) to investigate the feasibility, effectiveness and implications of the proposed mitigation measures;

(x) to identify, predict and evaluate the residual (i.e. after practicable mitigation) environmental impacts and the cumulative effects expected to arise during the construction and operation phases of the Project in relation to the sensitive receivers and potentially affected uses;

(xi) to identify, assess and specify methods, measures and standards, to be included in the detailed design, construction and operation of the Project which are necessary to mitigate these residual environmental impacts and cumulative effects and reduce them to acceptable levels;

(xii) to design and specify environmental monitoring and audit requirements and

(xiii) to identify any additional studies necessary to implement the mitigation measures or monitoring and proposals recommended in the EIA report.

1.5 Structure of the EIA Report

1.5.1.1 The background of the project, purpose and objectives of this Report are introduced in this section. A description of the Project and details of options consideration are provided in Section 2. Sections 3 to 10 detail the results of the environmental impact assessment of each key subject area, covering relevant legislation, environmental conditions, assessment criteria, methodology, and assessment findings.

1.5.1.2 Sections 3 to 10 are outlined as follows:

· Section 3: Air Quality Impact

· Section 4: Noise Impact

· Section 5: Water Quality Impact

· Section 6: Waste Management Implication

· Section 7: Land Contamination

· Section 8: Ecological Impact (Terrestrial and Aquatic)

· Section 9: Landscape and Visual Impact

· Section 10: Hazard to Life

1.5.1.3 An outline of the requirements for the Environmental Monitoring and Audit (EM&A) programme is presented in Section 11. The EM&A programme is presented in details in a separate EM&A Manual. A detailed implementation schedule of the recommended mitigation measures is provided in Section 12. A summary of environmental outcomes and conclusions is presented in Section 13.

1.5.1.4 This EIA Report consists of the following booklets:

· Volume 1 of 3 – Main Text (This booklet)

· Volume 2 of 3 – Figures

· Volume 3 of 3 – Appendices

1.5.1.5 An Executive Summary has been prepared as a separate document in both Chinese and English, which contains summaries of the key findings, recommendations and conclusions of the EIA Report.

List of Figures
Figure 1.1	Location of Proposed Yuen Long South Effluent Polishing Plant (YLSEPP)

List of Appendices
Appendix 1.1	Checklists for EIA Study Brief, Annexes 11 & 20 of EIAO-TM